Epidemiology of snakebites
[1] An analysis cross-referencing exposure to venomous snakes and accessibility of medical treatment identified that 93 million people worldwide are highly vulnerable to dying from snakebite.
[a][17] The black mamba (Dendroaspis polylepis), although responsible for fewer snakebite incidents, is the species which has the highest mortality rate in Africa and in the world (per capita) if left untreated.
Before the advent of a polyvalent antivenom produced by the South African Institute for Medical Research, black mamba envenomation was certain to cause fatality (100% rate).
[22] Mambas, cobras, and some larger puff adder species may claim territories of up to 1 to 2 square kilometres (0.4 to 0.8 sq mi), which are used by the snakes for hunting and reproduction.
[23] Although black mambas cause only 0.5-1% of snakebites in South Africa, they produce the highest mortality rate and the species is responsible for many snake bite fatalities.
The black mamba is the species with the highest mortality rate in every single nation in which it occurs, despite not being responsible for the most numerous snakebites.
Since these snakes are nocturnal and fossorial, living in burrows underground, bites remain rare, peaking at 1 to 3% in certain areas of the Sudanian savanna.
However, there is no antivenom or other effective therapy for Atractaspis envenomation, and the case fatality rate remains approximately 10%, with death typically occurring quickly.
[28] Agricultural plantations and pastoral areas are involved in approximately 50 to 60% of reported snakebites,[22] while outdoor activities such as collecting firewood and water account for another 20% of bites.
[15] Approximately 1 million snakebites occur in sub-Saharan Africa each year,[29] resulting in up to 500,000 envenomations, 25,000 deaths and another 25,000 permanent disabilities.
[29] Most victims who receive treatment by health care professionals have nevertheless delayed seeking medical attention for over 24 hours, and often up to 1 to 2 weeks.
[29] In many sub-Saharan countries, poor availability of expensive antivenom contributes to morbidity, and snakebites continue to remain a neglected health problem.
[32][33] According to the most conservative estimates, at least 81,000 snake envenomings and 11,000 fatalities occur in India each year, making it the most heavily affected country in the world.
However, in the Philippines, more than a quarter of Aeta men (a modern forest-dwelling hunter-gatherer group) have reported surviving a reticulated python attack.
[36] Throughout Western Asia, the species responsible for the majority of bites tend to be more venomous than European snakes, but deaths are infrequent.
[citation needed] The vast majority of venomous snakebites in Australasia occur outside of Australia, in the surrounding islands.
[1] The majority of bites in New Guinea are caused by the death adders, and a smaller number by the endemic small-eyed snake and other local species.
Of the five dangerous groups, the highly venomous eastern brown snake, which is widespread and common in both rural and urban environments, is the most important—it is estimated to be responsible for up to 60% of all deaths caused by snakebite.
[38] Several venomous colubrids exist in Australia as well, such as the brown tree snake, although they have geographically limited distributions and only very rarely deliver a medically significant bite.
[41] Despite the fact that many Australian snakes have unusually potent venom, wide access to antivenom, which is available for all dangerous species,[38] has made deaths exceedingly rare.
[19] Although Europe has a population of some 731 million people, snake bites are only responsible for between 1 and 7 (average of 4) fatalities each year,[42][43] largely due to wide access to health care services and antivenom, as well as the relatively mild potency of many native species' venom.
[43] The best estimate is that the annual incidence of snakebites in Europe (including European Russia and Turkey) is 1.06 [0.97–1.15] per 100,000 inhabitants,[42] only about 15% of which are severe bites.
[42] Bites from captive venomous snakes to a very specific and limited population of amateur herpetoculturists, zookeepers, and researchers are an issue in Europe,[44][45] challenging hospital workers with unexpected situations.
[53] Colubrid species found in Central America only cause mild to moderate envenomation in healthy adults, and most of these bites have occurred in humans handling the snakes.
[53] Panama may have the greatest incidence of snakebites in Latin America, while El Salvador has the lowest (mostly because B. asper is not found in this country).
[65] While the majority of species live close to shorelines or coral reefs, the fully pelagic yellow-bellied sea snake can be found in the open ocean.
